Method of and apparatus for stopping leaks in the casing of oil and gas wells



July 28, 1925. 1,548,012

. l. L. `DUNN METHOD OF AND APPARATUS FOR STOPPING LEAKS IN THE CASING- OF OIL.AND GAS WELLS Filed Nov. 10 1924 2 Sheets-Sheet l I, I INVENToR.

I ATTORNEYS.

July 28, 1925.

2- Sheets-Sheet 2 l. L. DUNN METHOD OF AND APPARATUS FOR STOPING LEAKS IN THE CASING 0F OIL AND GAS WELLS D Filed Nov. 10 1924v IN VEN TOR ATTORNEYS.

Patented July 2,8, 1925.

UNITED STATES PATENT OFFICE.

IRWIN I. DUNN,-O'F MARIETTA, OHIO.

GAS WELLS.

Appiicaton led November 1924. Serial-No. 748,928.

To all whom 'it may' cmwem:

Be it known that I, IRWIN L. DUNN, a citizen of the United l States, residing at Marietta, in the county of Vashington and State'of Ohio, have invented certain new and useful Improvements in Methods of and Apparatus for Stopping Leaks in the Cas.

ing of Oil and Gas l/Vells, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to methods ofand apparatus for stopping leaks in the casing of oil and gas wells without removing the casing from the wells.

It is customary in the oil fields to line the walls of the well with casing that is securely seated above the productive measures, in order to exclude water,^mud, cavings and other materials that otherwise would enter the well and would seriously and often ruinously alect the production of the oil and the operation of thewell. Frequently such casing develops leaks after insertion in the well.` Leaks may be through the couplings ornnder the casing seat, or they-may be caused by holes being eaten through the casing source, e leaks must be stopped for otherwise the production of oil will be interfered with to the extent that its economic value' vmay be destroyed and thousands of wells have been destroyed 'in this manner.

^ I-Ieretofore it has been the practice either to withdraw the casing to repair defects, or if the casing could not be removed or was too badly damaged, to insert anv inner string of,4 ipe. A more recent practice has been to end) avor to shut off leaksby pouring mudluid, `sand umpings or like material behind the casing with the purpose of causing the fluid to work .down the annular space between thecasing and the walls of the hole l orbetween the casing and the next larger string of casing and carrying fragments of'- rock or other material that will'clo'g up the leak and lilter outpthe mud till a tight seal is formed either at the leak o r in the annu lar space adjacent to the leak and thus prevent water or other -material entering through the defective parts.` A-

The methods ,ofwithdrawing` the casing and repairing it or of inserting an inner string of pipe are very expensive while the method of using lmud-fluid or sand pumpings frequentlyfails of its purpose because of la corrosive waters, but of Whatever Referring first to the apparatus for carryobstructive materials behind the casing that prevents the fluid from reaching the sources 'of trouble or beca-use the hole through or under the casing may be'too large to be clogged up readlly-and attempts to repair the well in this manner may lead to irreparable damageby letting'mud in on the productive measures.

.-My present invention has for its object to provide a method and means for carrying outl said method whereby leaks in Well casingsmay be stopped more ,cheaply 'and eii'ectively and without' removing the casing from the well. This I accomplish by ap?. plying pressure internally of the well casing and forcing the pressure out through any leak in said casing and up the annular space behind the casing, loosening bridges or obstructing material and allowing the repairing fluid to obtain access to the leaks, or repairing the leak by agitating the material adjacent the leak whereby any frag'- ments of rock or other material that would. tend to clog up the'leak may have the 0pportunity of settling back and so doing. i

In the accompanying drawings Fig. 1 is a partial vertlcal sectional view and side elevation of my apparatus shown jin relation to a well;

' METHOD 0F AND APPARATUS FORI'STOPPING LEAKS IN THE CASING 0F OIL-AND' Fig.,3 is also a similar vieW of a part of the casing showing a modification, and;

Fig. 4 1s a simllar view lshowing another form of carrylng out my invention.

ing out my invention, in Fig. 1, I' have shown the same installed in a well and the conditions which may exist behind the well casing'before pressure is applied. The-numeral 1 indicates a bored well having a pit 2. A casing is fitted into the well bore and terminates somewhat above the pit 2, thel casing being open at its lower end and closed at its upper end by any suitable form of packed casing head 4.. In the present 1n.- stance, I have, shown an L type of head having a large discharge line 5, secured thereto with a gate valvevtheren operated by any suitable means, as shown at 6. A gage 7` is inserted in the discharge line between the casing head and the valve to determine the amount of pressure being exerted within the l. casing when the valve -is closed and the apparatus is in operation. A pipe 8 is suspended in the casing 3 through the packed casing head 4 and is supplied with suitable pressure medium, such as air or gas under pressure, through suitable' connections. In the supply line for the pressure medium there is a .valve 10 to regulate the supply and a gage 11. The'packed casing head 4 is also provided with an opening which receives meansA for introducing additional pressure medium into the casing to assist the supply introduced through the pipe line 8 in creating suiiicient lpressure within the casing to force the pressure medium through the leak and agitate the material outside of the casing. This means comprises a supply line 13 having a valve 12 to regulate the amount of pressure medium thus introduced into the casing.

A plug 9 is inserted in the well below the casing to protect the oil measures while the leak is being repaired. In the practices of present methods of repairing leaks without removing the casing, one diliculty is the obstruction to the passage of the fluid to the leak by bridges which are formed adjacent the casing between the top of same and the leak, as shown at 14 in Fig. 1. Unless these bridges are broken up the fluid cannot reach the desired destination. The present method of agitating the material on the outside of the casing loosens up such obstructions or bridges and permits an obstruction or bridge to be built up adjacent the leak and thus repair the leak in this manner, or the fluid is permitted to pass down to the leak if the pouring method is being used. When the fluid is employed, a conductor pipe 15 is inserted at the surface to direct the fluid in its downward course adjacent the outside of the casing. The leaks in the casing are indicated by the reference numerals 16.

Referring to Fig. 2, I have shown means for confining the pressure medium to a limiting area in the casing. This is desirable sometimes when the casing has more than one leak, as in this way the lowest leak may be repaired and then succeeding higher leaks. With the form here illustrated, it is not necessary to have a tight casing head, the desired space in the casing being made air tight by a packer carried by the pipe 8. Any form of packer may be used, but in the present instance I have shown a cup packer inverted on the pipev and comprising a swedge nipple or reducer 17, a spreader 18 and leatherrcup 19. In operation the pressure medium is introduced through the pipe 8 and confined in the space between the plug 9 and the cup packer whence it is forced out through the. leak to agitate the surrounding material, after which the pressureV may be removed and the leak repaired iu the. manner heretofore set forth.

In Fig. 3 I have shown means especially adapted for repairing large leaks in well casings. In this instance the pressure mer diuni supply pipe is sealed at the lower end as shown at 20, and is provided with a series of openings 2l, below and above which are located cup packers similar to the packer described in connection with Fig. 2. l In the operation of this form the pressure medium isdelivered to .the casing `through the holes 2l and confined in the space between the two cup packers, whence it is forced through the leak to iagitato the surrounding material,

and the process of sealing the leak effected casing 3 and capped at its lower end by a` plug similar to the plug 20 shown in Fig. 3. The pipe 8 has attached thereto, a bag 22, of any suitable material, such as canvas, leather vor rubber, and the space between the points ofa-ttaclnnent of said bag is provided with openings 23 through which the pressure medium passes.. In operation the pipe 8 is so positioned in the well that that part of the same to which the bag is attached will be in the locality ofthe leakto be repaired. The pressure medium is then turned'on and rushes through holes 23 infiating the bag until its sides expand flush with the sides of the casing 3, thereby preventing any foreign material from entering the well through the leak 16 in the casing. Any suitable material is then introduced fr'oln the top of the well behind the casing and prevented from entering the casing until the coarser materials have settled out and.. formed a bridge adjacent the leak, which seals the same against entrance of foreign material.`

Referring now to my method-'of stopping out removing the same from the'well, I first `introduce a plug or bridge of any suitable kind in the well beyond the leak to protect the oil measures `below. I theninsert 'apipe into the well through a packed casing head at the top of the casing. I then apply pressure medium to the inserted pipe whereby the water or other material within the easing and above the plug may be ejected through a large discharge pipe secured to the casing head. When such materials have been removed I close the gate ou the discharge pipe and confine the pressure in the well. When the pressure medium in the casing is sulicient to overcome the pressure outside the casing -it passesl through the leaks and lifts and agitates the material behind the casing. I then remove the pressure and vvent the well and the material behind the lcasing settles back in the annular space, with the result that the leak will be sealed, *providing the ,material behind the leak carries fragments sion, I introduce a fluid behind the casing from the surface and work it down to the.

defective parts by alternately building up Vpressure within the casing and releasing it.

l sometimes find it desirable to mix witlithe fluid, chopped rope, straw, sawdust, sand,

',lead shot or .other like material to aid iu clogging the leaks, depending upon the char.- a'cter of the leak-and the nature of the surrounding' material.

f It is sometimes difficult to repair more than one leak at a time and I therefore carry out my method in such cases by con.

.lining the pressure'to a limited area in the casing, the pressure medium acting in the sai-ne manner as above stated. Again, if the leak in the casing consists of a large hole, I may carry out my method by confining the air pressure ina receptacle suspended in the casing which prevents any forei matter from entering theI casing. as by orming a bridge in the manner heretofore referred tol in which a fluid is introduced behind thecasing at the top thereof and carried down to the leak.

. It, will be understood that I desire to comprehend withinl my invention such modifica-- tions as may be necessary to adapt it to varying conditions and uses. 5

Having thus fully described my invention,

-wliat I claim as new and desire to secure by Letters Patent is 1. A method of stopping leaks in oil or gas well casings consisting in inserting a plug below theleak and above vthe oil vor gas bearing measure; in introducing a pressurel medium into said casing; in blowing out any water or other material in said casing; in then sealing said casing above the leak to confine the pressure medium therein; and in forcing the pressure medium out, through any leaks in said casing to agitatethe material outside of said casing.

2. A method of stopping casings consisting in inserting a plu below the leak and above the oil or gas ming measures; in introducing a pressure medium into said casing; in blowing out any air or other material 1n said casing; yin then sealing leaks in' wen said casing above the leak to confine the pressure medium therein; in forcing said pressure medium through any leaks .in said casing to agitato the material outside of said casing a-nd in then removing the pressure and Venting the well casing above the leak i any bein to permit the coarser materials behind the l casin to settle back and seal the leak.

3. method of stopping lea-ks in oil vor gas well casings consisting in inserting *a plug below the leak and above the oil or gas bearing measure; in introducing a pressure medium into said casing; in blowing out Water or other material in said casing; in then sealing said casing above the leak to confine the pressure medium therein; in forcing the pressure medium out through any leaks in said casing to agitate the Jmaterial outside of said casing; and in introducing a sealing fluid adjacent the quter .wall of said casing at the surface of! the ground adaptedto seal theleak.

.4. A method of stopping leaks lin oil or gas well casin s consisting in inserting a plug below the eak and above the oil or gas bearing measure; in introducing a pressure medium into said casing; in blowing'out any water or other material in saidcasing; in then sealing said casing above theleak to confine the pressure mediu'in therein 'in forcing the pressure medium out through any leaks in said casing to agitate the material outside of said casing; in introducing a sealing Iiuid adjacent the outer wall of said casing atthe surface of the ground; and in and above theI through the leak an agi-' that part of. said casing containing the leak i being repaired to permit the coarserv materials behind the casing toA settle back and seal the leak.

6. A method of stopping leaks in oil or gas well casings consisting 4in inserting a plugV below the lowest leak and above the oil bearing measures; in positioning a plugin the casing above said lowest leak; mi 1ntroducing and confining a pressure medium between said plugs; in forcingthe pressure medium through the leak and agitating the material on the outside of said cas' in in' troducing a sealing fluid adjacent, t e outer walls of said casing at the surface of the ground; that part of said casing containin the leak repaired to permit the intro need sealuid to seal the leak.

said casing and in removing the pressure froml A Imethodof 'stopping leaks in oil or gas wells consisting in inserting a'iplug in below a leak, and another plug in said casing above said leak; introducing a pressure medium into said casing between said plugs; in forcing the pressure medium through the leak in said casing to agitate the material on the outside of same;

andin removing the pressure from that a pressure medium into said casing betweenl said plugs; in forcing the pressure medium through the leak in said casing to agitate the material on the outside of same; introducing au sealing uid adjacent the outer wall of said casing at the surface o-the ground; -and in removing the pressure from 'that part of 'said casing containing the leak being repaired to permit the introduced fluid to seal the leak.

9. In an apparatus of the character de scribed,- the combination with a casmg, means for introducing a pressuresmedium into said casing, and means for confining said pressure medium in said casing and forcing it through a hole in said casing to agitate the material on the outside of said casing, of a' -plug for preventing the pressure medium from coming in Contact with the oil bearing measures.

l0. In an apparatus of the character described,- the combination with a casing, a pipe suspended in said casing adapted to carry a pressure medium into said casing, anda plug carried by said pipe whereby the pressure mdium may be retained in said casing below said plug, of another plug inserted below said casing and above the oil or gas bearing measures to prevent the pres# sure medium from having access thereto.

In testimony whereof; I affix my signature. v

IRWIN L. DUNN. 

